Cardiovascular regulation: associations between exercise and head-up tilt.
Can J Physiol Pharmacol
; 97(8): 738-745, 2019 Aug.
Article
em En
| MEDLINE
| ID: mdl-30917299
ABSTRACT
It was hypothesized that faster cardiorespiratory kinetics during exercise are associated with higher orthostatic tolerance. Cardiorespiratory kinetics of 14 healthy male subjects (30 ± 4 years, 179 ± 8 cm, 79 ± 8 kg) were tested on a cycle ergometer during exercise with changing work rates of 30 and 80 W. Pulmonary oxygen uptake ( ) was measured breath-by-breath and heart rate (HR), mean arterial blood pressure (MAP), and total peripheral resistance (TPR) were measured beat-to-beat. Muscular oxygen uptake ( ) was estimated from HR and . Kinetic parameters were determined by time-series analysis, using cross-correlation functions (CCFmax(x)) between the parameter and the work rate. Cardiovascular regulations of MAP, HR, and TPR during orthostatic stress were measured beat-to-beat on a tilt seat. Changes between the minima and maxima during the 6° head-down tilt and the 90° head-up tilt positions were calculated for each parameter (Δtilt-up). correlated significantly with ΔTPRtilt-up (r = 0.790, p ≤ 0.001). CCFmax(HR) was significantly correlated with ΔHRtilt-up (r = -0.705, p = 0.002) and the amplitude in HR from 30 to 80 W (rSP = -0.574, p = 0.016). The observed correlations between cardiorespiratory regulation in response to exercise and orthostatic stress during rest might allow for a more differential analysis of the underlying mechanisms of orthostatic intolerance in, for example, patient groups.
Palavras-chave
cardiorespiratory kinetics; cardiovascular regulation; cinétique cardiorespiratoire; exercice physique; exercise; expériences de basculement; forme physique; orthostatic stress; orthostatic tolerance; physical fitness; régulation cardiovasculaire; stress orthostatique; tilting experiments; tolérance orthostatique
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fenômenos Fisiológicos Cardiovasculares
/
Exercício Físico
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Decúbito Inclinado com Rebaixamento da Cabeça
Tipo de estudo:
Risk_factors_studies
Limite:
Adult
/
Humans
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Male
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article